Therefore, the model demonstrates that oxygen-related physiological characteristics (pulmonary blood source, residual volume, oxygen diffusion coefficient, baseline macrophage O2 consumption) combined with immune-related physiological characteristics that bring oxygen-consuming cells to the site of infection (chemokine diffusion constant, Tmove, CCL5 threshold) integrate to determine how quickly hypoxic regions occur and how long they are maintained. The gene discussed is CCL5; the disease is infection.